Engine



R. T. LARSEN Aug. 3, 1965 ENGINE 2 Sheets-Sheet 1 Filed Dec. 9, 1963 INVENTOR. ,Fffr Z'ZMJf/v BY M, M, M

Aug. 3, 1965 R. T. LARsEN 3,198,162

ENGINE Filed Dec. 9, 1963 2 Sheets-Sheet 2 Mam/M United States Patent O ENGENE Robert T. Larsen, Menomonee Falls, Wis., assigner to Outboard Marine Corporation, Waukegan, Ill., a corporation of Delaware Filed Dec. 9, 1963, Ser. No. 329,036 42 Claims. (Cl. 11S-17) The invention relates to exhaust gas discharge arrangements for marine propulsion devices such as outboard motors and stern drive units which are powered by an internal combustion engine.

The invention provides a lower unit including an exy haust gas tube which communicates with the exhaust gas f cushions supporting the exhaust gas tube.

The provision of both a water jacket surrounding the 'exhaust gas tube, together with the resilient mounting thereof, serves to isolate the engine exhaust excitations from the sound radiating surfaces of the lower unit,

thereby providing vibrational and sound isolation between Ythe exhaust gas tube and the lower unit and producing a quieter operating device. In addition, the use of a jacketed exhaust tube serves to reduce the temperature of the gases flowing through the exhaust gas tube.

Other objects of the invention will become known by reference to the following description and accompanying drawings in which FIG. l is a side elevational view7 partially broken away and in section, of an outboard motor embodying various yof the features of the invention;

FIG. 2 is a fragmentary side elevational view7 partially broken away in section, of a second embodiment of an `outboard motor in accor-dance with the invention;

FIG. 3 is a side elevational view, partially broken away in section, of another embodiment of an outboard motor incorporating various of the features of the invention;

FIG. 4 is a fragmentary side elevational view, partially broken away and in section, lof a fourth embodiment of an outboard motor in accordance with the invention; and

FIG. 5 is 'an enlarged sectional View taken along line 5 5 of FIG. 4.

The outboard motor 11 shown in FIG. 1 is representative of various marine propulsion devices, such as outboard motors and stern drive units, in which various of the features of the invention can be embodied. The outboard motor 11 conventionally includes a transom bracket 13 to which a swivel bracket 15 is connected for vertical swinging movement a'bout a horizontal pintle 1'7. Carried from the swivel bracket 15 for horizontal or dirigible swinging movement, by pivot means including a vertical kingpin 19, is a propulsion unit 21 including a power head 23 and a lower unit 25. Included in the power head 23 is an internal combustion engine 27 including an exhaust gas dis-charge port 29.

Included in the lower unit 25 is an exhaust gas passage means in the form of a passage 31 and a part 25 which is normally submerged in water during operation and which includes 4means (not shown) for supporting a propeller 33 and for driving the propeller from the engine 27.

The propulsion unit 21 can be vibrationally isolated from the swivel bracket 15 in various ways, such as the arrangements disclosed in the Irgens Patent No. 2,740,368 and in the Watkins Patent No. 3,002,489.

ice

In accordance with the invention, the exhaust gas passage 31 is formed in part by -a sleeve member or tube 35 which is resiliently supported by cushion mounts from the remainder of the lower unit 25, thereby isolating the lower unit 25 from any vibration which may be imparted to the sleeve yor tube 35 |by the exhaust gas flow. Thus, in the construction shown in FIG. 1, a cushion 37 is interposed between the upper end of the sleeve 35 and a hanged ring 39 at the lower end of a tubular portion 41 of the lower unit, which portion communicates with the engine exhaust gas discharge port 29. As its lower end, the sleeve 35 is carried by cushion 43 mounted adjacent to the lower unit exhaust gas outlet 45.

Also provided in the lower unit around the exhaust gas passage 31 is a water jacket 47 which serves to cool the passage 31 and to deaden transmission to the lower unit 25 of the vibration or sound excitations which are associated with engine exhaust gases. The water jacket is formed through the cooperation of an outer wall 49 of the lower unit 25 and a partition 51.

Means are provided for supplying water to the jacket 47 and for discharging water from the jacket. In the embodiment shown in FIG. 1, such means is in the form of an opening or scoop 53 communicating with the jacket 47, depending from the lower unit 25 and including an inlet rearwardly of the propeller 33, whereby propeller rotation serves to introduce water into the jacket 47 through the scoop 53.

At its upper end, -above the cushion 37, the outer wall 49 of the lower unit is provided with means for discharging -or overliowing water from the jacket. In the embodiment shown in FIGURE l, such means comprises a port 55 from which water supplied to the jacket 47 is discharged. This arrangement has the advantage of providing coolant convection flow laround the exhaust gas passage 31 and of affording coolant flow into the vicinity of the cushions 37 and 43 yso as to avoid deterioration thereof. y

In the outboard motor 111 shown in FIG. 2, the engine 127 includes an exhaust gas port 129 with an extension 157 which projects into the lower unit 125 clear of any contact with the lower unit. At its lower end, the extension 157 is provided with a anged ring 139 which carries an upper cushion 137 in which the upper end of a sleeve is supported. The use of an extension 157 projecting into the lower unit clear of contact therewith serves to avoid the possibility of transmitting vibration and sound to the lower unit portion 41 shown in FIG. 1. In other respects, the construction of the outboard motor 127 is the same as the outboard motor 27 shown in FIG. 1.

In the outboard motor 211 shown in FIG. 3, the propulsion unit 221 includes a lower unit 225 and a power head 223 which are jointed together by a sound and vibrational barrier 259, including a resilient member or pad 260, as disclosed in my copending application entitled Engine, Serial No. 328,813. Included in the power head 223 is a crankshaft 262. Also included in the lower unit 225 are portions of an engine cooling system including a conventional water pump 261 driven by a driveshaft 264 which is connected to the crankshaft 262 and to a clutch mechanism 266. The water pump 261 supplies coolant to the engine 227 and communicates with an inlet line 263, a discharge line 265 and a recirculating line 267. The driveshaft 262, discharge line 265, and recirculating line 267 are passed through the barrier 259, including the resilient member or pad 260, in accordance with the disclosure of said copending application.

As in the other embodiments, the lower unit 225 includes an exhaust gas passage 231 including a sleeve 235 which is resiliently supported on its upper and lower ends by respective cushions 237 and 243. The cushion 243 pending application. s

silient pad 2,60 incorporated yin the barrier 259. In this .'regard', the resilient pad includes fa gas discharge aperture '2&9 and, at the lower-'end thereof, a counterbore271 which provides a seat for the upper end of the sleeve 235.

The lowerV mounting plate 273 ofthe barrier 259 includes an aperture 275 of suchV size so that there is no contact between the plate 273 and the sleeve 235.

`The pad 260 in the Vvicinity ofv the aperture 269 canbe cooled by various arrangements, for instance, as bythe arrangements'disclosed in my said copending apphcatlon.

Water discharge from the engine water jacket 385 for `recirculation returns to theV` pump through the recirculatingline 367. rWater discharged from the engine water jacket 385 for' discharge from the motor 311 travels through a ydischarge port in communication with a bore or passage 395 (see FIG'. 5) which passes through the connection between the. lower unitv 325 and the power head 323 and which communicates with a second arcuate passage 397 around the cushion 337. In turn,`the arcuate passage 397 communicates with a portor passage 399 which drains the dischargeyfrom the engine water jacket As in the other embodiments, the exhaust gas passage."fk

231 is provided with a water jacket 247 formed by part of the outer wall 249 of the lower unit 225 and a parti-'f tion 251. However, inthe embodiment shown in FIG.. 3, an idle relief exhaust arrangement is provided. Specically, the lower unit is provided with an auxiliaryV chamber 277'which includes an exhaust port 255 and which,

at a point below the bottom of the uppery end of the f exhaust port, communicates with the water jacketV 247 385 into the water jacket 347 surrounding the exhaust gas passage 331. Thus,-in Vthe embodiment shown in FIG.

4, water for the jacket 347 surrounding the Yexhaust gas passagev 331 is 'providedby the dischargefilow from the engine water jacket 385., This ow also seri/ esito asslst .Vrin cooling the cushion 337. Water'is drained from the through an aperture 279 in the wall 249 of the lower*y unit225. At a point above the `normal level of theV water in the jacket 247, the sleeve 235 is provided with a port 281 permitting low of exhaust gas, under idling conditions, into the jacket 247 forow through the aper-v ture 279 into the'auxiliary chamber 277l and outy of the exhaust port 255.y Y

Asalso in the other embodiments, means are providedl jacket 347 in thesame manner as in the outboard motor 211 shown in FIG. 3. Other arrangements such as, for example, the passages. disclosed yin my saidcopending application, `can be Vemployed to cool the upper cushion Various v.of the features of the invention are set forth in the following claims.

What is claimed is: l l Y Y 1. In a marine propulsion device, anrengine having an exhaust gas discharge port, and a'lower unit including for supplying water to and discharging water from the.

jacket. In the embodiment shownin FIG. 3,'water is supplied by ya branch line 283 which communicates between the waterpump discharge line 265 and the water .jacket 247.7and'whichis of relatively-small cross section ascompared to the size of the water pump discharge line 265. Dimensioning of `.the branch line l233 with a rela- .tively small, cross sectional size atords flow tothe exhaust gas water jacket 247 whileralso assuring waterflow to the engine cooling jacket 285.

Additional muiiing advantages are as to establish a normal. water level in the water jacket 247 below the bottom ofthe upper end of -the port 255 and slightly above theaperture 2.79, thereby normally providing'for a smallV depth of Water through which the provided bydis- Y charging the water ow yfromy the jacket 247 into the ex" haust gas passage 231. Speciiically an inverted L-shaped v pipe 287 is mounted on the sleeve -235 and communi-V .cates between the water jacket 247. `and theinteriorw'of the passage 231. The legQ289 of the pipe'is'located sof engine exhaust ypasses under idling conditions. In .the

event `thatthe pipe 287 becomes blocked-,fthe disclosed Vconstruction permits discharge from the water jacket 247 through the aperture 279, chamber 277 andthe port 255.

While the outboard motor` 211 is show n in'FIG.`-3with 'a recirculating type of engine coolingfsystem, the advantages of the inventioncan alsobe obtained whenV using Y either of the so-called bypass or restriction types and when using othercoolant passage arrangements in the vicinity of the aperture 269, asdisclosed'for instance, in said co In the outboardmotor 311 shown ink FIG. 4, the lower unit 325. 'isdirectly connected to the, power lhead 323 and the upper cushion 337 is Alocated Vin the'lower unit.

which, in( turn, communicates with another bore or'pasv sage r393* extending Vthrough the connection betweenthe f lower unit 325 and Vthe power head 323 for communication with the engine'water jacket 385'.; l' ,Y

exhaust `gas passage meansV communicating with said exhaustgas discharge port of said engine, saidv gas passage means includingran, exhaust gas tube, and resilient means l interposedfbetween"said tube and said exhaust ygas discharge port, whereby said gas tube nection with said engine.

2. In a marine propulsion device comprising an engine havingra water dischargeV port,a lower unit including an is free ofrigid con- Y exhaust gaspassage means including an outletl opening and dening a Water jacket surrounding said tube, water inlet means communicating with said water jacket, and water discharge'means communicating with said waterjacket.

3. In an outboard motor,the combination of va power head including anY internal v,combustion enginehaving au exhaust gas discharge portga lower unit, meansresiliently connecting said lower Yunit and said power head, exhaust 'gas passage means in' said lower unit communicating with said exhaust rgas discharge. port and including an outlet below said power head, and an exhaust gas tube communi cating with said discharge port and said outlet, and vresilient means'supportingsaidtube in said lower unit and interposed between said exhaust lgas discharge port and said tube. l Y

4. An outboardY motor-'inV accordance with claim 3 wherein-said resilientV means'suppoyrting said tube and interposed between` said exhaust gas y.discharge port and said -tube includes a part ofsaid means resiliently con- Ynectingjsaid lower unit and said power head.

5. Anioutboard motor in accordance with `claim 3 in furthercombination withmeans in said` lower unit'delining a water jacket surrounding'saidl tube, water linlet meansrin said lowerv unit communicating with said water an exhaust gas tube, resilient means interposed between said tube whereby said gas tube is free of rigid connection with said engine, and said exhaust gas discharge port, andfcoolant passage means in adjacent location to said resilient means.

9. In a marine propulsion device, an engine having an exhaust gas discharge port and a lower unit including exhaust gas passage means communicating with said exhaust gas discharge port, said gas passage means including an exhaust gas tube, resilient means interposed between said tube and said exhaust gas discharge port, whereby said gas tube is free of rigid connection with said engine, and means defining a water jacket in said lower unit in surrounding relation to said tube.

10. A marine propulsion device comprising an engine `having an exhaust gas discharge port, a lower unit including an exhaust gas passage means including an outlet opening and an exhaust gas tube communicating with said outlet opening and with said exhaust gas discharge port, resilient means interposed between said tube and said exhaust gas discharge port, whereby said gas tube is free of rigid connection with said engine, means dening a water jacket surrounding said tube, water inlet means communicating with said water jacket, and water discharge means communicating through said tube between said water jacket and said exhaust gas passage means.

11. A marine propulsion device comprising an engine lhaving an exhaust gas discharge port, a lower unit including an exhaust gas passage means including an outlet opening, and an exhaust gas tube communicating with said opening and with said exhaust gas discharge port, resilient means interposed between said tube and said exhaust gas discharge port, means defining a water jacket surrounding said tube, water inlet means communicating with said water jacket, water discharge means communieating with said water jacket, and a port communicating with the atmosphere and with said water jacket, said port including means above said water discharge means to allow drainage from said water jacket in the event of blockage of said water discharge means.

12. In an outboard motor, the combination of a power yhead including an integral combustion engine having a water jacket and an exhaust gas discharge port, a lower unit connected to said power head, exhaust gas passage means in said lower unit communicating with said exhaust Vgas discharge port and including an outlet below said *said discharge port and said outlet, resilient means interposed between said tube and said exhaust gas discharge port, a water jacket surrounding said exhaust gas tube, and a water pump carried by said lower unit and communicating separately with said engine water jacket and said water jacket surrounding said exhaust gas tube.

13. An outboard motor in accordance with claim 12 wherein'water dischargemeans communicates through said exhaust gas tube for discharge of coolant through said exhaust passage means.

14. In an outboard motor, the combination of a power head including an internal combustion engine having an exhaust gas discharge port, a lower unit connected to said power head, exhaust gas passage means in said lower unit communicating with said exhaust gas discharge port and including an outlet below said power head, and an exhaust gas tube communicating with said discharge port and said outlet, and resilient means interposed between said tube and said exhaust gas discharge port, a water jacket surrounding said tube, water inlet means in said lower unit communicating with said water jacket, and water discharge means in said lower unit communicating with said water jacket and located above said water inlet means.

1S. In a marine propulsion device, the combination of an engine including an exhaust gas discharge port, and a lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, an exhaust gas tube, and means mounting said tube in said lower unit free of rigid connection with said engine and in communication with said outlet and said engine exhaust gas discharge port, and means defining a water jacket surrounding said exhaust gas tube.

16. In a marine propulsion device, the combination of an engine including an exhaust gas discharge port and a water jacket, said water jacket having a discharge port, and a lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, an exhaust gas tube, and means mounting said tube in said lower unit free of rigid connection with said engine and in communication with said outlet and said engine exhaust gas discharge port, and means defining a water jacket surrounding said exhaust gas tube and communicating with said water jacket discharge port, said means defining a water jacket including means affording discharge of water from said jacket at a point spaced substantially above the bottom of said jacket.

17. An outboard motor comprising a transom bracket, a swivel bracket connected to said transom bracket for pivotal movement about a horizontal axis, and a propulsion unit connected to said swivel bracket for pivotal movement about a generally upright axis, said propulsion unit comprising an engine and a lower unit, said engine including an exhaust gas discharge port, said lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, an exhaust gas tube, and means mounting said tube in said lower unit in communication with said outlet and said exhaust gas discharge port, and means defining a water jacket surrounding said exhaust gas tube and extending within said lower unit from below to above the lower end of said swivel bracket.

18. An outboard motor comprising a transom bracket, a swivel bracket connected to said transom bracket for pivotal movement about a horizontal axis, and a propulsion unit connected to said swivel bracket for pivotal movement about a generally upright axis, said propulsion unit comprising an engine and a lower unit, said engine including an exhaust gas discharge port, said lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, an exhaust gas tube, and means mounting said tube in said lower unit in communication with said outlet and said exhaust gas discharge port, means defining a water jacket surrounding said exhaust gas tube and extending within said lower unit, and means affording overflow of water from said jacket at a point spaced substantially above the bottom of said jacket.

19. An outboard motor comprising a transom bracket, a swivel bracket connected to said transom bracket for pivotal movement about a horizontal axis, and a propulsion unit connected to said swivel bracket for pivotal movement about a generally upright axis, said propulsion unit comprising an engine and a lower unit, said engine including an exhaust gas discharge port, said lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, an exhaust gas tube, and means mounting said tube in `said lower unit in communication with said outlet and said exhaust gas dis- -a swivel bracket connected to said transom bracket forl pivotal movement about ahorizontal axis, and a propulsion unit connected to said .swivel bracket for pivotal movement about a generally "upright axis, lsaid propulsion unit y'comprising an engine "land a lower unit, said engine including anexhaust 'gas discharge port, said low- Y d Ver unit including Vexhaust gas passage means, said exhaustY "gas passage meansdncluding an outlet, an exhaust gas tube, and means mounting said tube in said lower unit `free of rigid connection with said engine and: in 'cornmunicationwith said outlet and said exhaust gas discharge port, and means delining'a water jacket surrounding said exhaust gas tube and extending within said low- Yer unit fromY below to above the'lower end of said-'swivel bracket, said means deiiningwaterjacket including means aifording discharge of water from said jacket at a point spaced substantially above the bottom of said jacket.

/ 21. Anoutboard motor comprisingl a transom bracket, 2a swivelbracket. connected to said transom bracket Yfor pivotal movement'about a horizontal axis, and a propulsion unit connected tosaidswivel vbracket for pivotal Vmovement about a generally upright axis, said propulsion unit comprising an engine and Va lower unit, said engine including an exhaust gas discharge portvr and'a'water jacket, said water jacket having a discharge port, said lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, `an exhaust lgas tube, and means mounting said'tube in said lower unit in communication with said outlet and said exhaust gas discharge port, and means 'dening a water jacket surrounding*said-exhaust gas tube and extending within said lower-unit from below 'j to above the lower end of said swivel bracket, said means deiining` a water jacket including means affording com-municationwith said en- "gine Vwater. jacket dischargeport, and meansfaliording discharge of water from vsaid jacket at a point spaced Asubstantially above the bottom of said jacket.

22. An outboard motor comprisinga transom bracket, a swivel bracket connected to said ltransom bracket for pivotal movement about a horizontal axis, and a propulsionl unit connected vto ,said swivel bracket for pivotal unit comprising an engine anda lower unit, said engine 'movement about a generallyr upright axis, said propulsion including an exhaust gas discharge port and a water jacket, said water jacket` having a discharge port, said Vlower unit including exhaustr gas Vpassage means,Y said exhaust gas passage means including an outlet, an `exhaust gas tube, and means mounting said tube` in said lower unit free of rigid connection with said engine and in communication with said/outlet and :saidexhaustgas ,means deining a rwater jacket 4surroundingsaidexhaust spaced relation Ato said drive a lower unit including exhaust gas passage means, said exhaustgas passage Vmeans including'and an outlet, `an exhaust -gas tube communicating with said outlet and said vengine exhaust gas discharge port, and means defining Va waterjacket surrounding said exhaust gas tube and -in- -cluding water discharge means located in an upper part of saidy jacket. v n

' 25. In a marine propulsion device, the combination'of 'an engine including an exhaust vgas discharge port and a llower unit including exhaust gas passage means,said exhaust gas passage meansincluding and an outlet, anexhaustrgas tube communicating with said outlet and said engine exhaustgas discharge port, and means defining a water jacket surrounding said exhaustl'gas tubeand including water overflow means establishing'a normal level of water in said jacket. v Y

26. In a marine propulsiondevice, the combination of an engine including an exhaust gas discharge port and a lower unit including exhaust-gas passage means including an outlet,'andfan exhaust gas passage means, said exhaust gas tube communicating with said outlet and said engine lexhaust gas ldischarge port, means deiininga water jacket surrounding 'said lexhaustgas'tubev and including water overliow means-establishing the vnormal'level of water in lsaid jacket, and an idle rexhaust gas relief means including a .wall portion insaid lower unit having therein means defining an apertureV communicating -with said water jacket belowsaid normal water level.

' 27. lIn a marineY propulsion device, the combination ofran engine including an exhaustflgas discharge port, and a lower lunit including exhaust gas passage means, said exhaust gas passage means including an '1outlet,'an exhaust gas tube communimating with said outlet and said engine exhaust gasl discharge'port, and means resilien-tly mounting the'lower end of said tube in said lower unit, and means defining ia water jacketl surrounding said exhaust gas tube. Y v u 28. In a marine propulsion device, the combination of an enginevincluding an exhaust g'as discharge port'and a lower unit'including exhaustgaspassage means, said 'ex `haust gaspassage means including angoutlet, an exhaust gas tube communicating with said outlet-'and said engine exhaust gas discharge port, and'means resiliently mounting the lowervend of saidvtubein'said jlowergunit, and means defining a water jacketjsurroundingl lsaid y exhaust gas tube and including an aperture adjacent the lower end Y gas tubecommunicating with saidoutlet andfsaid engine I exhaustgas discharge port, andmeans resilientlymountf discharge port, l.and meansA deiining a water jacketsurrounding said exhaust gas tube and extending within said lower unit from below to above the lower end of said swivel bracket, Ysaid ,means defining n a water jacket including'means laffording'communication withysaid engine water jacket dischargev port, andrmeansj-:afording discharge of waterfromsaid jacket at a Apoint spaced-V substantially aboveV the bottom of said jacket.

' 23. In a marine propulsion device, the combinationy of engine including a crankshaft and an exhaust gas dis# Vcharge port, and a .lower unit including va vertically extending drive shaft connectedv to said Vcrank shaft,tand exhaust gas; passage d means, said exhaust gas passage 4means including an outlet, an exhaust gas tube, and means mounting said tube in said lower unit free of rigid vcornvnection with said engineand in communication with said outlet and fsaid engine exhaust gas discharge port, 'and ing the upper 'end of said tubej'andmeans definingv l'a wa-Y jterjacketsurrounding saidexhaust'gas tube. f

30. In a marine propulsiondevice, the combinationof an engine including an exhaust gas discharge port, and

'd a'lower unitincluding a,part-'normallysubmergedinwater during'normal'.operation, exhaustggas passage means including an outlet "located ,ini said part, Aand an exhaust gas tube communicating -witlisaid outlet and said engine exhaust gas dischargeA port, and means dening a water v Y"jacket surrounding said exhaust gasvtube` and extending upwardly 'from in water.:

adjacent to said fpart'lnormally .submerged 31. Ina marine propulsion `device,r the combination of l 'an engine including,v an exhaustgas dischargerport, and a lower unit includinga'l part normally. submerged in waterduring normal operation, and "exhaust Vgas passage means, said exhaust Y'gas passage means includingfandan outlet located in said part, an exhaust gas tube communieating with said outlet and said engine exhaus-t gas dischargeport, and means defining a water jacket surrounding said exhaust gas tube and extending upwardly from adjacent to said part norm-ally submerged in water, said water jacket including an opening adjacent the lower end thereof.

3,2. In a marine propulsion device, the combination of an engine including an exhaust gas discharge port and a lower unit including a part normally submerged in water, and an exhaust gas passage means, said exhaust gas passage means including an outlet, and a free standing exhaust gas tube in communication with said outlet and said engine exhaust gas discharge port, said tube extending upwardly in said lower unit from adjacent to said normally submerged part, and means defining a water jacket surrounding said exhaust gas tube.

33. In a marine propulsion device, the combination of an engine including an exhaust gas discharge port, and a lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, an exhaust gas tube, and means resiliently mounting said tube in said lower unit and in communication with said outlet and said engine exhaust gas discharge port, means defining a water jacket surrounding said exhaust gas tube, and means defining an aperture in said tube communicating with said water jacket.

34. An outboard motor comprising a transom bracket, a swivel bracket connected to said transom bracket for pivotal movement about a horizontal axis, and a propulsion unit connected to said .swivel bracket for pivotal movement about a generally upright axis, said propulsion unit comprising an engine and a lower unit, said engine including an exhaust gas discharge port and a crank shaft, said lower unit including a drive shaft connected to said crank shaft, exhaust gas passage means including an outlet, an exhaust gas tube, and means mounting said tube in said lower unit in communication with said outlet and said exhaust gas discharge port, and means defining a water jacket surrounding said exhaust gas tube and extending upwardly Within said lower unit from below the lower end of said swivel bracket and in spaced relation to said drive shaft.

35. An outboard motor comprising a transom bracket, a swivel bracket connected to said transom bracket for pivotal movement about a horizontal axis, and a propulsion unit connected to said `swivel bracket for pivotal movement about -a generally upright axis, said propulsion unit comprising an engine and a lower unit, said engine including an exhaust gas disch-arge port, said lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, an exhaust gas tube,

f and means mounting said tube in said lower unit and in communication with said outlet and said exhaust gas discharge port, and means dening a water jacket surrounding said exhaust gas tube and extending upwardly within said lower unit from below the lower end of said swivel bracket, said means deiining a water jacket including means defining an opening adjacent to the bottom of said jacket.

36. In an outboard motor, the combination of a power head including an internal combustion engine having an exhaust gas discharge port, and a lower unit having therein exhaust gas passage means communicating with said exhaust gas discharge port and including an outlet below said power head and an exhaust gas tube communicating with said discharge port and said outlet, said lower unit also having therein means resiliently supporting said tube. 37. A marine propulsion device comprising an engine having an exhaust gas discharge port, a lower unit including exhaust gas passage means including 4an outlet opening, and an exhaust gas tube communicating with said opening and with said exhaust gas discharge port, resilient means interposed between said tube and said exhaust gas discharge port, means defining a water jacket surrounding said tube, water inlet means communicating with said water jacket, water discharge means communicating with said water jacket, a port communicating with the atmosphere and with said water jacket, said port including means above said water discharge means to 4allow drainage from said water jacket in the event of blockage of said water discharge means, an auxiliary chamber cornmunicating with said port and with said water jacket at a point below the normal water level in said water jacket as defined by said water discharge means, and means communicating between said exhaust gas passage means and said water jacket above said normal water level.

3S. In an outboard mot-or, the combination of a propulsion unit, and means adapted to be connected to a boat transom and connected to said propulsion unit for affording dirigible movement of said propulsion unit, said means for aiording dirigible propulsion unit movement including pivot means extending generally vertically when said propulsion unit is in normal operating position, said propulsion unit comprising a power head including -an internal combustion engine having an exhaust gas discharge port, and a lower unit connected to said power head and including exhaust gas passage means communicating with said exhaust gas discharge port and comprising an outlet below said power head, and a resiliently mounted exhaust gas tube communicating with said discharge port and said outlet and extending in said lower unit from adjacent to the lower end `of said pivot means, and means defining a water jacket surrounding said exhaust gas tube.

39. An outboard motor comprising a propulsion unit, means adapted to be connected to a boat transom and connected -to said propulsion unit for affording dirigible movement of said propulsion unit, said means affording dirigible propulsion unit movement including pivot means extending generally vertically when said propulsion unit is in normal operating position, said propulsion unit comprising an engine and a lower unit, said engine including an exhaust gas discharge port, said lower unit comprising exhaust gas passage means including an outlet, an exhaust gas tube, and means mounting said tube in said lower unit in communication with said -outlet and said exhaust gas discharge port, and means defining a Water jacket surrounding said exhaust gas tube and extending within said lower unit from below to above the lower end of said pivot means.

40. In a marine propulsion device, the combination of an engine including an exhaust gas discharge port and a lower unit including exhaust gas passage means, said exhaust gas passage means including ran outlet and an exhaust gas tube communicating with said outlet and with said engine exhaust gas discharge port, means deiining a water jacket surrounding said exhaust gas tube and including means establishing a normal level of wa-y ter in said jacket, and an aperture located below said normal water level and communicating with said exhaust gas tube for exhaust gas flow through said water jacket and through said aperture.

41. In a marine propulsion device, the combination of an engine including an exhaust gas discharge port and a lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet and an exhaust gas tube communicating with said outlet and with said engine exhaust gas discharge port, means defining a water jacket surrounding said exhaust gas tube and including water `overflow means establishing -a normal level of water in said jacket, and an idle exhaust gas relief means including means defining an aperture located below said normal w-ater level and communicating with the interior of said exhaust gas tube.

42. In a marine propulsion device, the combination of an engine including an exhaust gas discharge port, and a lower unit including exhaust gas passage means, said exhaust gas passage means including an outlet, and exhaust gas tube communicating with said outlet and said engine 151i.V d Y l 12 exhaust gas diseha'rge port., and xnensin said lowerf'unit.y y 72,261,948' T11/41 Bech 181--42 yresiliently mounting said ztube, and means defining .a wa- 2,652,802 9/53771Ca11'soni 2; .115-17 ter jacket surrounding said exhaust gastube. Y 2,909,031 10759 l Kiekhaefer. 60-31 I I Y V3,045,423 7,/62'1Hu1sebus 11s-17 X.

References Cited bythe Examiner 5 Y- l l v f Y f UNITED STATES PATENTS Y l FOREIGNL'PATEIJTS 1,318,158 10719 'Larsh f 181- 42 Xk j 531,451 3/60 Grajt Bfltam- 1'734911 [29 Kpg et al 115`17 MILTON BUCHLER; Primary Examiner.

1,786,835 12/30 Eviltlrnde` i115-17 Y Y 1 f 2,204,294 v 6/40 Blanchard f 60-31 X 10 DAVID BLAKESLEE, Exllm'l'n'er. K

UNITED sTATLs PATENT oFFICE CERTIFICATE OE CORRECTION Patent No. 5,198,162 August 3, 1965 Robert T. Larsen It is hereby certified that error appears in the above numbered patant requiring correction and that the said Letters Patent should read as :orrected below.

Column Z, line 11, for "As" read At column 4, line 35, for "a water" read an exhaust g column 5, line l0, after "exhaust", first occurrence, insert gas lines 14 and 15', strike out "said tube whereby said gas tube is free of rigid'connection with said engine, and said exhaust gas discharge port," and insert instead said tube and said exhaust gas discharge port, whereby said gas tube is free of rigid connection with said engine, line 55, for "integral" read internal column 7, lines 50 and 51, strike out "unit comprising an engine and a lower unit, said engine movement about a generally upright axis, said propulsion" and insert instead movement about a generally upright axis, said propulsion unit comprising an engine and a lower unit, said engine column 8, line 7, strike out "and" and insert the same before "an", second OCCUTTenCe, same line 7; line 16, strike out "and" and insert the same before "an", second occurrence, same line 16; line Z4, after "means" insert said exhaust gas passage means line Z5, strike out "exhaust gas passage means, said".

Signed and sealed this 22nd day of February 1966.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. IN MARINE PROPULSION DEVICE, AN ENGINE HAVING AN EXHAUST GAS DISCHARGE PORT, AND A LOWER UNIT INCLUDING EXHAUST GAS PASSAGE MEANS COMMUNICATING WITH SAID EXHAUST GAS DISCHARGE PORT OF SAID ENGINE, SAID GAS PASSAGE MEANS INCLUDING AN EXHAUST GAS TUBE, AND RESILIENT MEANS INTERPOSED BETWEEN SAID TUBE AND SAID EXHAUST GAS DISCHARGE PORT, WHEREBY SAID GAS TUBE IS FREE OF RIGID CONNECTION WITH SAID ENGINE. 